Polycarbonates from dimers of alkenyl phenols



United States Patent 3,294,746 POLYCARBONATES FROM DIMERS OF ALKENYL PHENOLS Alford G. Farnham, Mendham, N.J., assignor to Union Carbide Corporation, a corporation of New York No Drawing. Filed Mar. 8, 1962, Ser. No. 178,287 2 Claims. (Cl. 260-47) This invention relates to dimers of alkenyl phenols, to a process for the preparation thereof and to products produced therefrom. More particularly, this invention relates to dimers of alkenyl phenols and to a process for the preparation thereof from the corresponding alkenyl phenol.

The dimers of the present invention have the general formula:

0 H F ormula I wherein each R, which on the same nucleus can be the same or dilferent, but are the same with respect to corresponding Rs on the other nucleus, are halogen atoms such as chlorine, bromine, iodine or fluorine, or alkyl, and when alkyl generally containing 1 to 4 carbon atoms inclusive and preferably containing 1 to 2 carbon atoms inclusive, as illustrated by methyl, ethyl, n-propyl, isopropyl, n-butyl and the like; each a is an integer having a value of 0 to 4 inclusive and with the further limitation that each OH group is in a position other than meta with respect to the group linking the aromatic nuclei.

Particularly desirable dimers for purposes of this invention are those having the general formula:

HO QOH' The alkenyl phenols from which the dimers of the present invention are produced have the general formula:

Formula II wherein R and a are as previously defined and OH is in a position other than meta with respect to the alkenyl group.

Compounds falling within the scope of Formula III can be conveniently prepared according to the procedures set forth by B. B. Carson et al. in 1. Organic Chemistry, 23 page 544 (1958).

The process, by which the dimers of the present invention are produced, is conducted by heating an alkenyl phenol falling within the scope of Formula III at a temperature of about 50 C. to about 200 C. and preferably at a temperature of about 85 C. to about 130 C. for a period of time sufiicient to dimerize the desired alkenyl phenol. At temperatures lower than about 50 C., little Formula III 3,294,746 Patented Dec. 27, 1966 h (R). (R a Hog Hog @011 Equation I wherein R, a and the position of each OH are as previously defined.

The pressure at which the dimerization reaction can be conducted can be atmospheric. subatmospheric or superatmospheric. It is preferred to conduct the reaction under atmospheric pressure.

The actual length of time that the alkenyl phenols are heated at the temperatures previously defined will, of course, vary and depend upon the alkenyl phenol which is being heated. As a rule, the heating cycle will vary from about 1 hour to about 4 hours. i

At the temperatures at which the dimerization reaction is conducted, the dimers which are formed are liquids. In order to recover the dimers which are formed, it is convenient to cool the dimers to room temperature, about 23 C. whereby the dimers solidify and are recovered as solids.

If desired, the dimers so produced can be recrystallized from suitable solvents in order to insure removal therefrom of unreacted monomer. Suitable solvents for this purpose include toluene, benzene, ethanol, cyclohexane and the like.

The dimers of the present invention, falling within the scope of Formula I, can be hydrogenated to form compounds which have the following formula:

C H; F ormula IV E quation II wherein R, a and the position of each OH are as previously described.

Particularly desirable hydrogenated dimers are those which have the following general formula:

HO OH Formula V wherein the position of each OH is as previously defined.

In conducting the hydrogenation reaction, it is convenient to dissolve the dimer in a suitable solvent, as for example, a saturated aliphatic alcohol such as ethyl alcohol, adding to the resultant solution a catalyst, which is capable of adsorbing hydrogen gas and thereafter donating a hydrogen ion, such as palladium and platinum, and subjecting the solution to a hydrogen gas atmosphere, at a temperature of about 20 C. to about 60 C. under a pressure of about 1 to about 3 atmospheres.

A more complete description of a suitable hydrogenation process is to be found in a book entitled, Reaction of Hydrogen, by Homer Adkins, University of Wisconsin Press, 1937.

Recovery :of the hydrogenated dimer can be conveniently accomplished by first removing the catalyst by filtration, and, depending upon whether the dimer is soluble or insoluble in the solvent at low temperatures, cooling the solution to precipitate out the hydrogenated dimer and recovering the dimeras a filter cake; or distilling of the solvent and recovering the hydrogenated dimer.

The dimers of alkenyl phenols and the hydrogenated compounds produced therefrom can be reacted with an epihalohydrin, in the presence of an alkaline catalyst, to produce the corresponding diglycidyl ethers.

The diglycidyl ethers produced from compounds fal ling within the scope of Formula I have the general 1 CH2(IJCH2O Formula VI The diglycidyl ethers produced from compounds fallformula:

R1 OCHz( OH2 Formula VII wherein in both Formula VI and Formula VII, R and a are as previously defined, R is hydrogen or methyl and each glycidyl ether group is attached to its aromatic group in a position other than meta to group linking the aromatic muclei.

Exemplary of suitable epihalohydrins that can be reacted with the dimers and the hydrogenated dimers to produce the corresponding diglycidyl ethers can be noted the epihalohydrins of the formula:

R1 l Cg27C-CH2X 0 Formula VIII wherein R is as defined and X is a halogen such as chlorine or bromine.

In conducting the reaction between an epihalohydrin and a dimer or its hydrogenated derivative, as defined, various amounts of reactants can be employed. Genera'lly, the amount of an epihalohydrin employed will be at least one mole per each OH equivalent of the dimer or of the hydrogenated dimer, and preferably from about 3 to about 4 moles of an epihalohydrin per OH equivalent. More than about 4 moles of an epihalohydrin per OH equivalent can be used, but this results in little improvement in the yield of diglycidyl ether.

The reaction between an epihalohydrin and a. dimer or hydrogenated dimer is usually carried out utilizing a catalyst which provides an alkaline medium for the reaction. As a rule, the catalysts used serve a dual purpose. Initially, they serve to catalyze the reaction of an epihalohydrin with the phenol to form the corresponding halohydrin ether and subsequently, they serve to dehydrohalogenate the chlorohydrin ether to the corresponding di-glycidyl ether.

For a detailed discussion of suitable procedures to be used in conducting the reaction between an epi-halohydrin and a phenol, including a discussion of suit-able catalysts, suitable reaction temperatures and the like, reference is made to US. Patent 2,943,045 to A. G. Farnham et al.

The diglycidyl ethers of this invention can be cured to infusible products using any of the epoxide curing agents.

Curing agents are generally classified as hardeners, that is, curing agents which themselves react with the diglycidyl ethers; or are classified as catalysts, that is, curing agents which promote the self-reaction of the diglycidyl ethers.

When used, the hardener is present inamounts of from about 75 percent of stoichiometric to about 15 percent in excess of stoichiometric and preferably from about percent of stoichiometric to about 10 percent in excess of stoichiometric, with respect to the amount of diglycidyl ether used.

In those instances wherein the curing agent used is a catalyst, the catalyst is used in amounts of from about 0.2 to about 5 percent by weight, preferably from about 0.5 to about 2 percent by weight, based on the weight of the diglycidyl ether.

Suitable curing agents are enumerated in my copending application Serial No. 168,830, entitled, Phenols, a Process for the Preparation Thereof and Products Produced Therefrom, the disclosure of which is incorporated herein by reference.

Curable compositions of this invention find utility as protective coatings on various surfaces, such as metal and wood, and as adhesives for bonding such surfaces together; as potting compositions for electrical components and the like.

The dimers and hydrogenated dimers of this invention can also be reacted with phosgene in a manner as described in US. Patent 2,970,131, Moyer et al., to produce thermoplastic polycarbonate resins. The polycarbonate resins so produced have the following recurring structural units:

wherein Ar is the residue of the dimer or of the hydrogenated dimer.

The dimers and hydrogenated dimers can also be used as antioxidants for synthetic rubber and as reactants with formaldehyde to produce phenolic resole resins.

Example I This example illustrates the preparation of a dimer which has the formula:

6 hydroxyphenyDpentane having a melting point of 111.5 C.

Anqlysis.--Molecular weight, found: 270. Calculated: 270. Percent OH, found: 12.2. Calculated: 12.6.

on 5 The hydrogenated dimer was shown to have the structure indicated by demonstrating that it gives, on reduction to remove the OH groups, the same hydrocarbon as does i the unsaturated dimer of alpha-methyl styrene upon hydrogenation. CH I CHFCCH2 O=P(0R o=1! (0R- C 3 OH OH 0 Two hundred and seventy-two grams of isopropenyl I g t y I I phenol having a boiling point of 115 C. at a pressure of p $81, 8 mm. of Hg were heated under a nitrogen gas atmosm i phere at a. temperature of 125 C. for 1 hour. The yel- 3, low liquid which had formed was cooled to a temperature 1 of about 115 C.-120 C. and seeded with crystals of the CH3 CH1(|3 CH3 dimer, whereupon the mass entirely solidified to a White OH; H OH; H solid tinged with yellow. 20

The solid was melted by heating to a temperature of Nalliq. NH; about 135 C., the melted product dissolved in hot toluene Col d i 10 0. Pd

CH3 C=CH2 CH 1CHzC=CHz OH -C-CHy-iJ-CH;

6H. as. It

and recrystallized out of solution by cooling the solution In the equations above R stands for the n-butyl radical. to a temperature of 5 C.

The dimer was recovered as a filter cake in the form Examp of white crystals which melted at a temperature of 127 C.-130 C. Two hundred and three grams of dimer were A mixture of 268 grams hnear dlmfar of recovered which represented a yield of seventy-five per- Phenol mole) grams F l cent by Weight. moles) and 150 grams etnyl alcohol was stirred in a r eac- Infraredanalysis of the dimer showed absorption bands flask and mam/tamed a temperature of 55*60 at 112' u to the 40 during the course of adding thereto 180 grams NaOH at the rate of 10% in the first hour, 10% m the 216x51 one-half hour, antfi 80% in the next hour. After a urt er reaction time o 15 minutes at 55-60 C., the refig gfi g ggi ilfx f the absorpnon that 15 shown aitizcgn 4rrkixture vzalslsubjetcted to distillation1 under;l pressuge o mm. o gwit agitation unt' t eresi ue pro Z: 5 2 i ggsggiggggggg h gfi gfg :3 5 45 not temperature reached 65 C. The residue product was chloro isopropenyl Phenol then cooled, dissolved in 1,000 cc toluene and the toluene solution washed several times with water to remove salt Example II and residual alkali. The washed toluene solution was then distilled under 25-50 mm. of Hg pressure to a resi- 052253312"?s eater:*ztsziaratir ri zsz grams viscous liquid product which showed on analysis formula an epoxy assay of 214 grams per epoxide equivalent.

0H OK It is to be understood that the disclosures of all patents I I 55 and literature references noted in this application are incorporated herein by reference. (J What is claimed is:

1. A thermoplastic polycarbonate having recurring structural units of the formula: CH OCH2CHCH 0 CH3 2-methy1-2A-bis (phydroxyphenyl) pentane TO O A I OT Into a mixture of 53.6 grams of the dimer described in Example I, 200 cc. of ethyl alcohol, 0.3 gram of a catalyst Is the resldue a compound having the composed of palladium adsorbed on charcoal (10 percent 0mm by weight of the catalyst was palladium), there was (Rla (Rh bubbled hydrogen gas under a pressure of 25 p.s.i.-40 p.s.i. for a period of 35 minutes. At the end of the 35- HO I OH minute period, the mixture was filtered removing the catalyst as the filter cake. The solution recovered was I I heated at a temperature of 70 C. and under a pressure of CH;, CCH2C=CH2 20 mm. of Hg with the result that the ethyl alcohol was 5 distilled oil.

The solid residue was recrystallized from toluene yieldwherein R is selected from the group consisting of haloing 50 grams of white, crystalline 2-methyl-2,4-bis(pgen and alkyl, a is an integer having a value of 0 to 4 7 8 inclusive and with the further limitation that each OH is 2,979,534 4/ 1961 Petropoulos et a1. 260619 in a position other than meta with respect to the group 3,049,568 8/1962 Apel et a1. 260619 linking the aromatic nuclei.

2. A thermoplastic polycarbonate as defined in claim 1 FOREIGN PATENTS :f/vhereilnAr is the residue of a compound having the 5 1,004,168 3/1957 Germany.

903,062 8/1962 Great Britain.

OH OH OTHER REFERENCES 1 C-orson, J. Organic Chem., vol. 23, pp. 544-549, April C-orson, et al., 1. Organic Chem, 23:544-546 (1958), 3 pp. I GH3(|3 OHC CH Derwent, Belgium Patents Report,- vol. 1, No. 78A 15 (May 16-31, 1961), page C-lO (Belgian Patent No.

597,434), 1 page. References Cited by the Examiner UNITED A S PATENTS WILLIAM H. SHORT, Primary Examiner. 2,806,016 9/1957 Schwarzer 260619 LEON J. BERCOVITZ, R. W. GRIFFIN, J. O MARTIN, 2,970,131 1/1961 Moyer et a1 26047 X 20 Assistant Examiners- 

1. A THERMOPLASTIC POLYCARBONATE HAVING RECURRING STRUCTURAL UNITS OF THE FORMULA: 